the documentation is outdated

[oubaydos]

For example:

export class Album extends Model<IAlbum> {
  // DynamoDB table name
  protected tableName = 'my_albums';
  // The keys of the table. Here it is a composite key (artist,album)
  protected hashkey = 'artist';
  protected rangekey = 'album';

  // Optionally override constructor
  constructor(item?: IAlbum) {
    super(item);
  }
}

the hashkey is no longer called that, instead it is called pk (same for rangeKet -> sk)